Package for a light emitting element

ABSTRACT

A high-brightness LED module includes a substrate with a recess in which a light emitting element is mounted. The recess is defined by a sidewalls and a relatively thin membrane. At least two micro-vias are provided in the membrane and include conductive material that passes through the membrane. A p-contact of the light emitting element is coupled to a first micro-via and an n-contact of the light emitting element is coupled to a second micro-via.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part application of and claimspriority to U.S. application Ser. No. 11/336,094, filed on Jan. 20,2006, the entire contents of which are hereby incorporated herein byreference.

TECHNICAL FIELD

This disclosure relates to a package for a light emitting device such asa light emitting diode.

BACKGROUND

Reduction in light emitting diode (LED) package size is an importantfactor in the design of various portable display technologies requiringcompact design such as cell phones or handheld computers. Traditionally,LED's are housed in packages that include multiple components whichoccupy an area much larger than the LED chip itself.

High brightness (HB) LED chips are being operated at ever-increasingpower levels. Generally, the light conversion efficiency of LED chips isfairly low such that heat generated by the LED chip has to be removed bythe package to the surroundings.

It is common that the combination of the LED substrate, the submount andthe package material are poorly suited for transferring heat from theLED chip to the surroundings. Highly thermally conductive material suchas metal mounts cannot be used alone because the electrical contacts tothe LED must be electrically isolated. While those contacts can beisolated, the necessary materials usually create a decrease in thethermal conductivity that limits the physical size and power of thechips that can be used in the package.

SUMMARY

Various aspects of the invention are recited in the claims. In oneaspect, a high-brightness LED module includes a substrate (also referredto as submount or platform) with a recess in which a light emittingelement is mounted. The recess is defined by sidewalls and a membrane.At least two through-holes filled with electrically conducting material(also referred to as micro-vias or through-contacts) are disposed in themembrane to electrically connect the light emitting element to theexterior of the package.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a cross-sectional view of an example of an opticalpackage.

FIGS. 2-4 illustrate various details of the package of FIG. 1.

FIG. 5 illustrates a circuit schematic of the LED and electrostaticdischarge (ESD) circuitry.

FIGS. 6A-6F illustrate various details of another example of an opticalpackage.

FIGS. 7A-7C illustrate various details of a third example of an opticalpackage.

FIGS. 8A-8B illustrate an implementation of an optical package thatincludes a lens.

FIGS. 9A-9B illustrate an implementation of an optical package thatincludes an array of LEDs.

FIG. 10 illustrates an implementation of an optical package thatincludes red, green and blue light emitting elements (RGBconfiguration).

FIG. 11 illustrates an implementation of an optical package thatincludes a lid and color conversion material.

DETAILED DESCRIPTION I. First Implementation

As shown in FIG. 1, a package 20 includes a lid 22, a recess 24 and asubstrate 26. One or more opto-electronic devices (light emitting orreceiving) may be mounted in the recess 24 between the substrate 26 andlid 22. In this particular implementation, the opto-electronic device isa light emitting diode (LED) 28.

The substrate 26 may comprise, for example, a semiconductor materialsuch as silicon (Si), so that the recess 24 may be formed by knownetching processes. Anisotropic wet etching solutions such as aqueouspotassium hydroxide may be used to form slanted sidewalls 30. In theimplementation of FIG. 1, at least one of the sidewalls 30 of the recess24 is slanted at an angle β of about 54.7°. The angle of the sidewalls30 may differ in other implementations. For dry etching techniques, suchas reactive ion etching, vertical sidewalls can be achieved. The etchingprocess leaves a thin membrane 25 of silicon on which the LED 28 issupported. The sidewalls 30 may be coated with a material, such asmetal, which acts as a reflecting surface 32 (see FIG. 2) to redirectlight exiting from the side walls of the LED 28 towards the lid 22.

The lid 22 can comprise a material such as glass or silicon that istransparent to at least a specified wavelength of light (or a band ofwavelength) emitted by the LED 28. In some implementations, the lid 22is positioned over and covers the entire recess 24 (see FIG. 3). Asshown in FIG. 2, a metal ring 34, which circumscribes the recess 24 maybe formed on the surface of the substrate 26. A hermetic seal may beformed when the lid 22, which is positioned over the entire recess 24,is fused to the metal ring 34 using, for example, a solder reflowprocess or a thermo-compression bonding process. Other sealingtechniques that do not require a metal seal ring 34 can be used as well,such as anodic bonding, glass frit bonding or epoxy bonding.

The LED 28 can be mounted in the recess 24, for example, by solder(e.g., eutectic AuSn metallurgy) or adhesive die attach techniques(using, e.g., either conductive or non-conductive adhesive). Wire bondscan be used to electrically connect contacts of the LED and micro-viasvia bond pads 35 a, 35 b, which are deposited and patterned at thebottom of the recess 24 (see FIGS. 1-2). Preferably, the bond pads 35 a,35 b comprise an electrically conducting material such as metal. Asshown in FIG. 1, the bond pads 35 a, 35 b can be provided on a portionof the surface of thin silicon membrane 25 which includes electricallyconductive feed-through material 38 formed in the thin silicon membrane25. The electrically conductive feed-through material 38 provideselectrical contact from the LED 28 and bond pads 35 a, 35 b throughsubstrate 26 to the package exterior. The conductive feed-throughmaterial 38 may be provided, for example, using an electroplatedfeed-through metallization process and allows the LED 28 to remainsealed hermetically within the package. Other deposition techniques,such as physical vapor deposition (PVD) or chemical vapor deposition(CVD) may be used as well. In a particular implementation, hermeticallysealing the through-holes includes providing a sandwiched stack ofdifferent materials, such as an adhesion layer, a plating base, afeed-through metallization, a diffusion barrier, a wetting layer, and ananti-oxidation barrier that comprises, for example, a noble metal. Inapplications where improved heat transfer between the package and anexternal support is desired, metal pads 39 a may be provided on thepackage exterior on a side opposite the recess 24 (see FIG. 4).Additionally, metal pads 39 b may cover and electrically connect toconductive feed-through material 38 as well as provide improved heattransfer to an external support. Metal pads 39 b may be used asunder-bump metallization (UBM) for solder interconnects to printedcircuit boards (PCBs).

To provide protection from damage to the LED 28 that may occur as aresult of excess electrical charge, electrostatic discharge (ESD)protection circuitry 40 can be formed in the thin membrane 25 region ofthe substrate 26 (see FIG. 2), for example, but not limited to, by aphosphorous and boron diffusion process. Preferably, the ESD circuitry40 is connected in parallel with the LED 28 through the bond pads 35 a,35 b. In the present implementation, for example, the ESD circuitry 40comprises two zener diodes 40 a, 40 b configured back-to-back. FIG. 5shows a circuit schematic of the ESD circuitry connected to the LED 28and an external voltage supply 42. When excess electrical charge createsa voltage (V) across the LED 28 that exceeds a threshold voltage, theESD circuitry 40 clamps the voltage (V) to a clamp voltage and diverts acurrent (I_(s)) from the LED 28. The threshold voltage and clamp voltageare determined by the breakdown voltages of the zener diodes underreverse bias and the threshold voltages of the zener diodes underforward bias.

II. Second Implementation

FIG. 6A illustrates a second implementation of an LED package 600. Thepackage 600, which includes substrate 626 and thin membrane 625, is insome implementations formed of silicon. The thermal conductivity ofsilicon is relatively high and the native silicon oxide can be used asan electrical isolator. Alternatively, thicker silicon oxide isolatorscan be obtained by thermal oxidation techniques. Also, silicon allowsthe use of surface mount technology (SMT), which is facilitated bymicro-via technology. Silicon also allows wafer-level processing of theLED die attachment, testing and lens attachment (see, e.g., FIGS.8A-8B). In instances in which the LED used in conjunction with the LEDpackage comprises a silicon substrate, silicon is advantageously usedfor the package material because compatibility of thermal properties(e.g., the coefficient of thermal expansion) of the LED and the LEDpackage are desirable. For example, it can be advantageous for thesubstrate and the LED to have similar coefficients of thermal expansion.

The package 600 includes a recess 624 defined by sidewalls 630 andmembrane 625. Sidewalls 630 can be metallized to form a reflectivecoating 630 a. Metallization of the sidewalls increases reflectivity andthe light output of an LED that is mounted in the recess 624. Whilemetals such as aluminum, silver or gold can be used to provide thereflective coating 630 a, other reflective materials are suitable(including non-metals). To preserve reflectance over time, thereflective coating 630 a can also include a protective coating such as,but not limited to, titanium oxide or silicon oxide. A protectivecoating may also comprise a variety of layers in a sandwichconfiguration, such as, but not limited to, silver-chromium compound,chromium, silicon oxide and silicon nitride. Also, in implementationsfor which it is desirable to scatter rather than reflect light from thecoating 630 a, the reflective coating 630 a can be roughened ortextured. Alternatively, the protective coating can be roughened ortextured. Scattered light from the coating 630 a would hit a lid 22 inshallow angles and reduce total internal reflection (TIR).

Bond pads 635 are disposed on the membrane 625. The bond pads 635, whichcan include a metal surface and solder, such as, but not limited to,eutectic AuSn solder, are arranged in a manner that corresponds with thecontacts of associated LED chip that will be mounted thereto. The bondpads 635 cover a significant amount of the membrane, which can beadvantageous for several reasons, including: (1) increased heat transferfrom the LED chip to the package 600 (e.g., as a result of the highthermal conductivity of the bond pads 635) and (2) distributing thecontacts across the LED surface generally increases the efficiency ofthe LED. Bond pads 635 are appropriate for use with, e.g., a flip-chipLED.

FIG. 6B is a cross-sectional view of package 600 taken through line B-Bof FIG. 6A. As the package 600 can comprise, for example, asemiconductor material such as silicon, the recess 624 can be formed byknown etching processes. Anisotropic wet etching solutions such asaqueous potassium hydroxide can be used to form the slanted sidewalls630. Depending on the implementation, at least one of the sidewalls 630of the recess 624 can be slanted at an angle (β) of about 54.7 degrees.The angle of the sidewalls 630 may differ in other implementations. Fordry etching techniques, such as reactive ion etching, vertical sidewallscan be achieved.

The cross-sectional view illustrates that the portion of the substrate626 that is thickest (i.e., measured by dimension A) forms a framearound the recess 624.

The etching process leaves a relatively thin membrane 625 on which anLED can be supported. Depending on the implementation, dimension A(i.e., the thickness of the frame portion of substrate 626) is betweenabout 100 and 700 microns (μm) and dimension B (i.e., the thickness ofthe membrane 625) is between about 40 and 150 microns. For example, inone implementation, dimension A is about 400 microns and dimension B isabout 60 microns. In another implementation, dimension A is betweenabout 100 and 300 microns and dimension B is between about 40 and 80microns. In another implementation, dimension A is about 410 microns anddimension B is about 55 microns. In another implementation, dimension Ais about 410 microns and dimension B is about 60 microns. In anotherimplementation, dimension A is about 650 micrometers and dimension B isabout 150 micrometers. In another implementation, dimension A is betweenabout 100 and 200 microns and dimension B is between about 40 and 80microns. In some implementations, dimension A is more than 6 timeslarger than dimension B. In some implementations, the maximum ofdimension A is between about 200 and 410 microns.

For example, in an implementation where dimension A (frame thickness) isabout 410 microns and dimension B (membrane thickness) is between about55 and 60 microns, dimension C (i.e., the width of the package 600)would be about 2 millimeters and dimension D (i.e., the width of themembrane 625) would be about 1.17 millimeters. Such an implementationwould be well-suited, e.g., for a 1 millimeter by 1 millimeter LED chip.Therefore, in such an implementation, the thickness of the membrane isless than 3/10 the LED chip dimension, is less than 1/10 the LED chipdimension, and is about 1/18 of the LED chip dimension. In such animplementation, the frame thickness is more than twice that of themembrane, and is almost seven times as thick.

Bevel 650, which can surround the entire package 600 (see, e.g., FIG.6C) is an etched feature that can facilitate solder inspection after thepackage 600 is mounted to a PCB. Bevels 650 are fully or partiallycovered with under-bump metallization (UBM) 639 a. During PCB mounting,the solder will form a meniscus shape that can be inspected by top viewmeans.

FIGS. 6C and 6D are perspective views of the package 600, illustrating(respectively) bottom and top views thereof. Bond pads 635 (see alsoFIG. 6A) are provided on a portion of the surface of the membrane 625,which includes electrically conductive through-contacts 638 formed inthe thin membrane 625. The electrically conductive through-contacts 638provide electrical contact from an LED (e.g., item 628 of FIG. 6E) andbond pads 635 through membrane 625 to the package 600 exterior. Bondwires or other electrical connections can be provided to connect the LEDto the bond pads 635. The conductive through-contacts 638 may beprovided, for example, using an electroplated feed-through metallizationprocess and allow the LED to remain sealed hermetically within thepackage. Other deposition techniques, such as physical vapor deposition(PVD) or chemical vapor deposition (CVD) may be used as well. Theconductive through-contacts 638 also can be formed by doping a portionof the silicon membrane 625. The conductive through-contacts 638 can bemicro-vias. Through-contacts 638 can have the shape of holes or planarareas. In some implementations, hermetically sealing the through-holesincludes providing a sandwiched stack of different materials, such as,but not limited to, an adhesion layer, a plating base, a feed-throughmetallization, a diffusion barrier, a wetting layer, and ananti-oxidation barrier that comprises, for example, a noble metal. Thethrough-contacts 638 can be electrically coupled to under-bumpmetallization pads 639 a that facilitate electrical connection to theLED mounted within the package 600. Of course, it is generally preferredthat the through-contacts associated with the n-contact of the LED beelectrically isolated from the through-contacts associated with thep-contact of the LED.

In applications where improved heat transfer between the package 600 andan external support is desired, a metal pad 639 b can be provided on thepackage exterior on a side opposite the recess 624 (see FIG. 6B). Themetal pad 639 b can be disposed directly opposite the LED such that heattransfer away from the LED is enhanced. The metal pad 639 b can beelectrically isolated from metal pads 639 a, or electrically connectedto either of the metal pads 639 a. In addition to providing electricalcontact, metal pads 639 a also can provide improved heat transfer to anexternal support.

FIG. 6E is a cross-sectional view of package 600 with an LED 628 mountedto the membrane 625. In this illustration, LED 628 is mounted using flipchip techniques and is coupled to the membrane 625 by way of bond pads635. The LED 628 is mounted to the membrane 625 without using a separatesub-mount. The optically active layer 628 a of the LED 628 causes it toemit light horizontally in a direction generally away from the membrane625.

In the example discussed in connection with FIG. 6B where dimension A isabout 410 microns, dimension B is between about 55 and 60 microns,dimension C is about 2 millimeters, and dimension D is about 1.17millimeters, and dimension E (i.e., the side length of the LED 628) isabout 1 millimeter. In some implementations, the LED 628 has anapproximately square plan view, such that its width and depth in thisperspective would be about equal (see FIG. 6F wherein dimensions E and Fare about equal). The LED chip 628 is about 80 microns thick.

FIG. 6F is a view of the contact side (i.e., the side opposite to theoptically-active side) of the LED 628. In this illustration, thecontacts are divided into two groups by dotted lines. The first group often contacts is the n-contact 628 n. The second group of six contacts isthe p-contact 628 p. Multiple contacts are advantageous, e.g., becausedistributing contacts across the LED surface increases LED efficiencyand the high heat conductivity of the contacts facilitate transferringheat from the LED 628 to the package 600. Because the membrane (e.g.,item 625) to which the LED is mounted is relatively thin, it effectivelytransfers heat out of the package 600. Heat transfer is further enhancedif the package is constructed of a material such as silicon. In thisimplementation, dimensions E and F are both about 1 millimeter.

III. Third Implementation

FIG. 7A illustrates a perspective view of a third implementation of anLED package 700. The package 700, which includes substrate 726 andmembrane 725, is in some implementations formed of silicon. The thermalconductivity of silicon is relatively high and the native silicon oxidecan be used as an electrical isolator. Alternatively, thicker siliconoxides can be formed by thermal oxidation techniques. Also, siliconallows the use of surface mount technology, which is facilitated bymicro-via technology. Silicon also allows wafer-level processing of theLED die attachment, wire bonding, testing and lens attachment (see,e.g., FIGS. 8A-8B). In instances in which the LED used in conjunctionwith the LED package comprises a silicon substrate, silicon isadvantageously used for the package material because compatibility ofthermal properties (e.g., the coefficient of thermal expansion) of theLED and the LED package are desirable.

The package 700 includes a recess 724 defined by sidewalls 730 andmembrane 725. Sidewalls 730 can be metallized to form a reflectivecoating 730 a. Metallization of the sidewalls increases reflectivity andthe light output from the package with an LED mounted in the recess 724.While metals such as aluminum, silver or gold can be used to create thereflective coating 730 a, other reflective materials are suitable(including non-metals). To preserve reflectance over time, thereflective coating 730 a also can include a protective coating such as,but not limited to, titanium oxide or silicon oxide. A protectivecoating may also comprise a variety of layers in a sandwichconfiguration, such as, but not limited to, silver-chromium compound,chromium, silicon oxide and silicon nitride. Also, because in someimplementations it is desirable to scatter rather than reflect lightfrom the coating 730 a, the reflective coating 730 a can be roughened ortextured. Alternatively, the protective coating can be roughened ortextured.

Contacts 751 a and 751 b are disposed on the membrane 725. The contacts751 a and 751 b, which can include a metal surface and solder coating,are arranged in a manner that corresponds with the contacts ofassociated LED chip (e.g., item 628) that will be mounted thereto. Thecontacts 751 a and 751 b cover a significant amount of the membrane,which can be advantageous for several reasons, including: (1) increasedheat transfer from the LED chip to the package 700 (e.g., as a result ofthe high thermal conductivity of the contacts) and (2) distributing thecontacts across the LED surface generally increases the efficiency ofthe LED. Contacts 751 a and 751 b are appropriate for use with, e.g.,flip chip LEDs with pre-deposited AuSn solder.

Contacts 751 a (which can be coupled to the p-contact of an LED) and 751b (which can be coupled to the n-contact of an LED) are coupled torespective test contacts 701. The test contacts are deposited andpatterned on the substrate and allow testing and/or burn-in of an LEDthat coupled to the contacts 751 a and 751 b. Test contacts 701 areadvantageous because it allows testing and/or burn-in without having to(1) mount the package 700 to a PCB or (2) flip the package 700 to exposethe through-contacts.

FIGS. 7B and 7C are perspective views of the package 600, illustratingbottom and cross-sectional views thereof. Contacts 751 a and 751 b (seealso FIG. 7A) are provided on a portion of the surface of the membrane725, which includes electrically conductive through-contacts 738 formedin the thin membrane 725. The electrically conductive through-contacts738 provide electrical contact from the LED (e.g., item 628) andcontacts 751 a, 751 b through membrane 725 to the package 700 exterior.The conductive through-contacts 738 can be provided, for example, usingan electroplated feed-through metallization process and allow the LED toremain sealed hermetically within the package. Other depositiontechniques, such as physical vapor deposition (PVD) or chemical vapordeposition (CVD) may be used as well. In some implementations,hermetically sealing the through-holes includes providing a sandwichedstack of different materials, such as, but not limited to, an adhesionlayer, a plating base, a feed-through metallization, a diffusionbarrier, a wetting layer, and an anti-oxidation barrier that comprises,for example, a noble metal. The through-contacts 738 can be electricallycoupled to under-bump metallization pads 739 a that facilitateelectrical connection to the LED mounted within the package 700. UBMpads 739 a can serve the additional purpose of conducting heat from thepackage 700 to the surface to which it is mounted.

Bevel 750, which can surround edges of package 700 proximate to themetal pads 739 a, is an etched feature that can facilitate, e.g., solderinspection after the package 700 is mounted to a printed circuit board(PCB). Bevels 750 are fully or partially covered with under-bumpmetallization (UBM) 739 a. During PCB mounting, the solder will form ameniscus shape that can be inspected by top view means.

The package 700 of this implementation can have the same dimensions as,for example, the implementation of FIGS. 6A-6E.

IV. Additional Advantages of a Silicon Substrate

FIG. 8A illustrates a cross-sectional view of a package 800 thatincludes a substrate 826 and a lens 875. The lens 875 can be used tofocus the light output of the LED and simultaneously seal the package,thereby protecting the LED. The lens 875 can be constructed of glass orplastic and can have optical properties designed for the implementation.

FIG. 8B illustrates an assembly process for the package 800, facilitatedby the use of a silicon substrate 826. Silicon wafer 826 w comprisesmultiple areas for individual LED package substrates 826 formed thereon.Lens sheet 875 s comprises a plurality of lenses 875 formed thereon. Byutilizing wafer level processing, multiple packages 800 can be formedsimultaneously, thereby decreasing production time and cost. Furtheradvantages of wafer level processes include encapsulation, functionaltesting and burn-in.

V. Additional Implementations

FIGS. 9A and 9B illustrate an implementation of package a 900 thatincludes an array of nine LEDs 928 a-928 i. This implementation can beuseful where a larger light output is needed than is possible from onesingle LED. The package 900 is larger than the previously describedimplementations, measuring approximately 2.6 millimeters by 2.6millimeters. The nine LEDs 928 a-928 i can be driven independently, ormultiple LEDs can be wired in series, parallel or any combinationthereof.

The package 900, which includes substrate 926 and thin membrane 925, isin some implementations formed of silicon. The thermal conductivity ofsilicon is relatively high and the native silicon oxide can be used asan electrical isolator. Alternatively, thicker silicon oxides can beformed by thermal oxidation techniques. Also, silicon allows the use ofsurface mount technology, which is facilitated by micro-via technology.Silicon also allows wafer-level processing of the LED die attachment,testing and lens attachment (see, e.g., FIGS. 8A-8B). In instances inwhich the LED used in conjunction with the LED package comprises asilicon substrate, silicon is advantageously used for the packagematerial because compatibility of thermal properties (e.g., thecoefficient of thermal expansion) of the LED and the LED package aredesirable.

The package 900 includes a recess 924 defined by sidewalls 930 andmembrane 925. Sidewalls 930 can be metallized to form a reflectivecoating 930 a. This increases reflectivity and the light output of anLED that is mounted in the recess 924. While metals such as aluminum,silver or gold can be used to create the reflective coating 930 a, otherreflective materials are suitable (including non-metals). To preservereflectance over time, the reflective coating 930 a may also include aprotective coating such as, but not limited to, titanium oxide orsilicon oxide, A protective coating may also comprise a variety oflayers in a sandwich configuration, such as, but not limited to,silver-chromium compound, chromium, silicon oxide and silicon nitride.Also, because in some implementations it is desirable to scatter thanreflect light from the coating 930 a, the reflective coating 930 a canbe roughened or textured. Alternatively, the protective coating can beroughened or textured.

FIG. 10 illustrates an implementation of package 1000 that includes anarray of three LEDs 1028 r, 1028 g and 1028 b. These LEDs emit,respectively, red, green and blue light. This implementation can beuseful in constructing a video display, e.g., using a plurality ofpackages 1000 as pixel elements. For video display use, it is generallypreferred that each LEDs 1028 r, 1028 g and 1028 b be drivenindependently. However, in implementations where this arrangement isused simply to provide high-brightness white light, the LEDs can bedriven together.

The package 1000, which includes substrate 1026 and membrane 1025, is insome implementations formed of silicon. The thermal conductivity ofsilicon is relatively high and the native silicon oxide can be used asan electrical isolator. Alternatively, thicker silicon oxides can beformed by thermal oxidation techniques. Also, silicon allows the use ofsurface mount technology, which is facilitated by micro-via technology.Silicon also allows wafer-level processing of the LED die attachment,testing and lens attachment (see, e.g., FIGS. 8A-8B). In instances inwhich the LED used in conjunction with the LED package comprises asilicon substrate, silicon is advantageously used for the packagematerial because compatibility of thermal properties (e.g., thecoefficient of thermal expansion) of the LED and the LED package aredesirable.

The package 1000 includes a recess 1024 defined by sidewalls 1030 andmembrane 1025. Sidewalls 1030 can be metallized to form a reflectivecoating 1030 a. Metallization increases reflectivity and the lightoutput of an LED that is mounted in the recess 1024. While metals suchas aluminum, silver or gold can be used to create the reflective coating1030 a, other reflective materials are suitable (including non-metals).To preserve reflectance over time, the reflective coating 1030 a alsocan include a protective coating such as, but not limited to, titaniumoxide or silicon oxide. A protective coating may also comprise a varietyof layers in a sandwich configuration, such as, but not limited to,silver-chromium compound, chromium, silicon oxide and silicon nitride.Also, because in some implementations it is desirable to scatter thanreflect light from the coating 1030 a, the reflective coating 1030 a canbe roughened or textured. Alternatively, the protective coating can beroughened or textured.

FIG. 11 illustrates a package 1100 comprising a substrate 1126, LED 1128and lid 1175. The lid 1175 comprises a color conversion layer 1175 a.The color conversion layer 1175 a can operate by filtering certainwavelengths of light, or may use a phosphor-type coating that is excitedby the light emitted by the LED 1128. The lid 1175 can be, for example,a Fresnel or diffractive type.

A number of implementations of the invention have been described.Nevertheless, it will be understood that various modifications may bemade without departing from the spirit and scope of the invention. Forexample, various features (including, e.g., the thickness of the thinsilicon membrane on which the LED mounted) described in connection withone of the foregoing implementations can be used in conjunction withother implementations as well. Accordingly, other implementations arewithin the scope of the claims.

1. An LED package comprising: an LED chip having an optically activelayer on a substrate; a platform, formed by a supporting framesurrounding a recessed membrane on which the LED chip is mounted inclose thermal contact to the material of the platform, wherein themembrane is provided with one or more electrically isolatedthrough-contacts made from electrically conducting material andconnected to respective electrodes of the LED chip.
 2. The LED packageaccording to claim 1 wherein the electrically conducting material is asemiconductor.
 3. The LED package according to claim 1 wherein theelectrically conducting material is a conductor.
 4. The LED packageaccording to claim 1, wherein the through contact has the shape of ahole or of planar areas.
 5. The LED package according to any one ofclaims 1-4, inclusive, wherein the LED has a side length dimension E,the thickness of the membrane is less than 3/10 the LED chip dimension(E) and the thickness of the supporting frame is more than twice themembrane thickness.
 6. The LED package according to any one of claims1-4, inclusive, wherein the LED has a side length dimension E, thethickness of the membrane is less than 1/10 the LED chip dimension (E)and the thickness of the supporting frame is more than twice themembrane thickness.
 7. The LED package according to any one of claims1-4, inclusive, wherein the LED chip is mounted in flip chip technologyand wherein the membrane comprises a plurality of through-holesrespectively filled with electrically conducting material and connectedto respective electrodes of the LED chip.
 8. The LED package accordingto any one of claims 1-4, inclusive, wherein the platform is made fromsilicon.
 9. The LED package according to any one of claims 1-4,inclusive, wherein the LED chip is mounted onto the platform withoutusing a separate sub-mount.
 10. The LED package according to any one ofclaims 1-4, inclusive, wherein walls surrounding the membrane form acavity and are arranged to reflect light emitted from the LED chip. 11.The LED package according to claim 10 wherein the walls of the cavityare coated with a reflecting material.
 12. The LED package according toany one of claims 1-4, inclusive, wherein the frame of the platform hasa thickness of at least twice the membrane thickness.
 13. The LEDpackage according to any one of claims 1-4, inclusive, comprising acolor conversion material disposed opposite the optically active layerof the LED chip.
 14. The LED package according to claim 1 wherein themembrane is between about 40 and 80 microns thick.
 15. The LED packageaccording to claim 1 wherein the frame is between about 100 and 200microns thick.
 16. The LED package according to claim 1 wherein theframe is between about 100 and 410 microns thick.
 17. The LED packageaccording to claim 1 wherein the LED chip is bonded to the membrane byadhesive die attach.
 18. The LED package according to claim 1 whereinthe LED chip is bonded to the membrane by solder die attach.
 19. The LEDpackage according to claim 11 wherein the reflecting material istextured so as to scatter light emitted by the LED.
 20. The LED packageaccording to claim 11 wherein the reflecting material is coated by aprotective layer.
 21. The LED package according to claim 1 furthercomprising a plurality of test contacts disposed on the frame, each testcontact electrically coupled to a respective electrode of the LED. 22.The LED package according to claim 1 further comprising a plurality ofmetal pads disposed on a surface of the platform opposite to a surfaceof the membrane to which the LED is mounted, the metal pads electricallycoupled to respective through-contacts.
 23. The LED package according toclaim 22 further comprising an aligned metal pad disposed on a surfaceof the platform opposite to the membrane surface to which the LED ismounted and substantially aligned with the location of the LED.
 24. TheLED package according to claim 23 wherein the aligned metal pad iselectrically coupled to one of the metal pads.
 25. An LED package,comprising; an LED chip having an optically active layer on a substrate;a submount comprising a central recessed membrane, wherein the LED chipis mounted on the membrane in close thermal contact to the material ofthe submount, the thickness of the membrane being less than 100 micronsand the thickness of a frame of the submount, which is integrally formedwith the membrane, is substantially larger than the thickness of themembrane.
 26. The LED package according to claim 25 wherein the submountis made from silicon.
 27. The LED package according to any one of claims25-26, inclusive, wherein walls surrounding the membrane form a cavityand are arranged to reflect light emitted from the LED chip.
 28. The LEDpackage according to claim 27 wherein the walls of the cavity are coatedwith a reflecting material.
 29. The LED package according to any one ofclaims 25-26, inclusive, wherein the frame of the submount has athickness of at least 300 microns.
 30. The LED package according to anyone of claims 25-26, inclusive, further comprising a color conversionmaterial disposed opposite the optically active layer of the LED chip.31. The LED package according to any one of claims 25-26 inclusive,wherein the membrane comprises at least a through-hole filled withelectrically conducting material and connected to an electrode of theLED chip.
 32. The LED package according to any one of claims 25-26,inclusive, wherein the LED chip is mounted in flip chip technology andwherein the membrane comprises a plurality of through-holes respectivelyfilled with electrically conducting material and connected to respectiveelectrodes of the LED chip.
 33. The LED package according to claim 25wherein the membrane is between about 40 and 80 microns thick.
 34. TheLED package according to claim 25 wherein the LED chip is bonded to themembrane by adhesive die attach.
 35. The LED package according to claim25 wherein the LED chip is bonded to the membrane by solder die attach.36. The LED package according to claim 28 wherein the reflectingmaterial is textured so as to scatter light emitted by the LED.
 37. TheLED package according to claim 28 wherein the reflecting material iscoated by a protective layer.
 38. The LED package according to claim 25further comprising a plurality of test contacts disposed on the frame,each test contact electrically coupled to a respective electrode of theLED.
 39. The LED package according to claim 31 further comprising aplurality of metal pads disposed on a surface of the submount oppositeto the membrane surface to which the LED is mounted, the metal padselectrically coupled to respective through-holes.
 40. The LED packageaccording to claim 31 further comprising an aligned metal pad disposedon a surface of the platform opposite to the membrane surface to whichthe LED is mounted and substantially aligned with the location of theLED.
 41. The LED package according to claim 40 wherein the aligned metalpad is electrically coupled to one of the metal pads.
 42. An LED packagecomprising; an LED chip having an optically active layer on a substrate,a submount comprising a central recessed membrane, wherein the LED chipis mounted to the membrane in close thermal contact to the material ofthe submount, the thickness of the membrane being less than 100 micronsand the thickness of a frame of the submount which is integrally formedwith the membrane, is substantially larger than the thickness of themembrane, wherein the submount is made from silicon.
 43. An LED package,comprising; an LED chip having an optically active layer on a substrate,a submount comprising a central recessed membrane, wherein the LED chipis mounted to the membrane in close thermal contact to the material ofthe submount, the thickness of the membrane being less than 100 micronsand the thickness of a frame of the submount, which is integrally formedwith the membrane, is substantially larger than the thickness of themembrane, wherein the membrane comprises at least one through-holefilled with electrically conducting material electrically connected toan electrode of the LED chip.
 44. A high-brightness LED modulecomprising: a silicon substrate comprising a recess defined by sidewallsand a membrane, wherein at least two micro-vias are disposed in themembrane, the micro-vias comprising conductive material that passesthrough the membrane; and a light emitting element mounted to themembrane, wherein a p-contact of the light emitting element is coupledto a first micro-via and an n-contact of the light emitting element iscoupled to a second micro-via.
 45. The module of claim 44 wherein a lidis attached to the substrate to define a region in which the lightemitting element is housed, and wherein at least part of the lid istransparent to a wavelength of light that the light emitting element isarranged to emit.
 46. The module of claim 44 including a reflectivecoating on sidewalls of the recess.
 47. The module of claim 46 whereinthe reflective coating substantially covers all surfaces of thesidewalls.
 48. The module of claim 46 wherein the reflective coatingcomprises metal.
 49. The module of claim 44 wherein an electricallyconductive feed-through material extends from the recess through themembrane to an exterior of the package.
 50. The module of claim 44comprising an array of LEDs.
 51. The module of claim 50 wherein thearray of LEDs comprises a red light emitting LED, a green light emittingLED and a blue light emitting LED.
 52. The module of claim 44 comprisinga lens coupled to the silicon substrate and arranged so that lightemitted by the LED passes through the lens.
 53. The module of claim 52wherein the lens comprises a color conversion material.
 54. The moduleof claim 52 wherein the thermal expansion coefficient of the siliconsubstrate is substantially similar to the thermal expansion coefficientof the LED.
 55. The module of claim 44 wherein the membrane is betweenabout 40 and 80 microns thick.
 56. The module of claim 55 wherein themaximum thickness of the silicon substrate is between about 200 and 410microns thick.
 57. The LED package of claim 25 wherein the frame of thesubmount has a thickness of about 410 microns and the membrane has athickness of about 60 microns.
 58. The LED package according to claim 1wherein the electrically conducting material is a metal.
 59. The LEDpackage according to claim 1 wherein the electrically conductingmaterial is a stack comprising a variety of metals.
 60. The LED packageaccording to claim 11 wherein the reflecting material comprises gold,silver, or aluminum.
 61. The LED package according to claim 1 whereinthe membrane is between about 100 and 200 microns thick.
 62. The LEDpackage according to claim 1 wherein the frame is between about 100 and700 microns thick.
 63. The LED package of claim 25 the membrane isbetween about 40 and 80 microns thick.
 64. The LED package of claim 25wherein the membrane is about 60 microns thick.
 65. The LED package ofclaim 25 wherein the maximum thickness of the frame is between about 200and 410 microns thick.
 66. The LED module of claim 44 wherein at leastone edge of the silicon substrate proximate to a micro-via comprises abeveled surface.
 67. The LED module of claim 66 wherein a micro-via iscoupled to a metal pad disposed on a surface of the membrane opposite towhich the LED is mounted, wherein at least a portion of the metal padextends to the beveled surface.
 68. The module of claim 55 wherein themaximum thickness of the silicon substrate is between about 400 and 700microns thick.
 69. The LED package according to any one of claims 1-4,inclusive, comprising a color conversion material disposed into thecavity.
 70. A light emitting device package comprising: a substrate; alight emitting device chip, having an optically active layer, on thesubstrate; and a platform, formed by a supporting frame surrounding arecessed membrane on which the light emitting device chip is mounted inclose thermal contact to the material of the platform, wherein themembrane is provided with one or more electrically isolatedthrough-contacts made from electrically conducting material andconnected to respective electrodes of the light emitting device chip.71. The light emitting device package according to claim 70 wherein thelight emitting device has a side length dimension E, the thickness ofthe membrane is less than 3/10 the light emitting device chip dimension(E) and the thickness of the supporting frame is more than twice themembrane thickness.
 72. The light emitting device package according toclaim 71 wherein the light emitting device chip is mounted in flip chiptechnology and wherein the membrane comprises a plurality ofthrough-holes respectively filled with electrically conducting materialand connected to respective electrodes of the light emitting devicechip.
 73. The light emitting device package according to claim 71wherein the platform is made from silicon.